Apparatus for packaging articles in a printed plastic sheet



Nov. 1, 1960 H. w.- LA BRANCHE APPARATUS FOR PACKAGING ARTICLES IN APRINTED PLASTIC SHEET Filed March 1, 1957 2 Sheets-Sheet 1 z e 4 2 3% mn5 N E r 4 MB 3 [G L w W H r A H m f e w 5 II n m w H 2 2 m m \CDWWLM i 78L 3 0 j... 4 M

Nov. 1, 1960 H. w. LA BRANCHE APPARATUS FOR PACKAGING ARTICLES IN APRINTED PLASTIC SHEET 2 Sheets-Sheet 2 Filed March 1, 1957 INVENTOR.Harvey WILa Bran chc M [292% Hf? g.

APPARATUS FOR PAQKAGENG ARTICLES IN A PRINTED PLA'STHI SHEET Harvey W.La Branche, Tacoma, Wash, assignor to Washington Steel Products, Inc,Tacoma, Wash, a corporation of Washington Filed Mar. 1, 1957, Ser. No.643,354

1 Claim. (Cl. 53-141) This invention relates to a method for packagingarticles in a printed plastic sheet.

In the packaging art it frequently is desirable to package articles insheets of clear plastic in order to protect the articles while stillpermitting inspection of them and display of their inherent beauty. Thismay be accomplished by heat softening a selected transparentthermoplastic material, wrapping it about the article while it issoftened and then cooling it to harden it.

In this procedure it is desirable to apply to the package a printedmessage indicating, for example, the character of the goods, theirsource and price, and related information. However, application of sucha printed message is difiicult of accomplishment because of thedistortion occurring in the plastic during the packaging operation.

Various procedures heretofore have been employed or suggested forachieving the desired result. In accordance with one method, thearticles are packaged in clear plastic against a cardboard backing sheetupon which the message is imprinted. This procedure is subject to thedisadvantage of increased cost attendant upon the use of the backingsheet, which costs nearly as much as the plastic itself and whichrequires special machinery and handling for its use. Also, the life ofthe backing sheet and the properties of the adhesive used for unitingthe backing sheet and the plastic sheet are variable. Still further, thefinal product is subject to warping because of the unbalancedconstruction.

In another proposed procedure the plastic packaging sheet is preprintedwith the message, allowance being made for the distortion occurringduring packaging with the object in view of pulling the message intoline during packaging. This is difficult of accomplishment, however,because of variable plastic properties, heater voltage, and atmosphericconditions. These and other factors make this procedure impractical andindeed preclude its application altogether where intricate work isinvolved.

Still further, it has been proposed to print the package after thepackaging operation has been completed. However, this requires a specialpress. Also, each of the diverse items packaged would require its ownspecial and costly printing platen designed to provide clearance for thepackaged article when the sheet is printed.

Accordingly it is the general object of this invention to provide amethod and apparatus for packaging articles in a printed plastic sheetwithout distortion of the printing to form a final package which isstable, inexpensive, and durable and which permits viewing of thepackaged article while reading the printed message directly associatedtherewith.

The manner in which the foregoing and other objects of this inventionare accomplished will be apparent from the accompanying specificationand claim considered together with the drawings, wherein:

Fig. l is a view in side elevation of apparatus which may be employedfor packaging articles in a printed plastic sheet in accordance with theherein described method, partly broken away to show the interior con2,958,172 Patented Nov. 1, 1960 struction, the sheet being positionedfor clamping and heating.

Fig. 2 is a sectional view taken along line 22 of Fig. 4 andillustrating the heat-softened, clamped sheet draped across thearticles;

Fig. 3 is a sectional view taken along line '33 of Fig. 4 andillustrating the sheet wrapped around the articles;

Fig. 4 is a plan view of the apparatus illustrated in Figs. 1-3; and

Fig. 5 is a perspective view of a package produced by the method of thepresent invention.

Generally stated, the herein described method of packaging articlescomprises providing a thermoplastic sheet having a printed portion,which it is desired to preserve undistorted, and a packaging portionwhich is to be Wrapped around the article. The sheet is placed across anarticle to be packaged with the packaging portion opposite the article.Heat is applied selectively to the packaging portion for softening thesame, after which the article and the sheet are moved relatively to eachother, wrapping the softened portion about the article. Thereafter thesheet is cooled for hardening it and forming the final package.

contemporaneously with the foregoing sequence, the margins of the sheetmay be softened selectively and pressed against a molding surface forforming a marginal bead about the package. This lends stiffness andrigidity to the package so that it may be handled more readily.

Considering the foregoing in greater detail and with particularreference to the drawings:

The presently described packaging method may be applied to the packagingof a diversity of miscellaneous items where it is desired to protect theitem, but at the same time permit inspection of it. Illustrative of suchitems are fishing lures, cutlery, small tools, door and drawer knobs,hinges, clusters of screws and bolts, and the like. For purposes ofillustration, it is described herein in connection with the packaging ofa plurality of screws 10.

To package the articles, they are placed in apparatus including aforming plate or platen 12 mounted on a table 14 having a smooth uppersurface area surrounding the formingplate.

The upper surface of plate 12 is subdivided by a plurality of ridges 16which define the plate areas to be employed for the production of eachindividual package. The interior of the plate is penetrated by a numberof communicating passageways all of which are connected to a source ofvacuum. As is evident from Fig. 3, these passageways include passageways18 located on both sides of ridges 16; passageways 20 located adjacentthe articles to be packaged; and central passageways 22, 24communicating with each other and with a duct 26 leading to a source ofvacuum, not illustrated.

Platen 12 is enclosed by a reciprocatable clamping frame assembly whichalso serves to define a vacuum forming box. In the illustrated form, thelower clamping frame 28 comprises a rectangular member dimensioned toenclose platen 12. Its undersurface is provided with a sealing ring 30which may be brought into sealing relationship with the smooth uppersurface of table 14. Piston rods 32 of fluid actuated cylinders notillustrated are connected to frame member 28 for reciprocating the frameassembly in a vertical direction.

A second sealing ring 34 is embedded in the upper surface of framemember 28. This ring functions to form a seal with a sheet ofthermoplastic material 36- which may be placed across the open top oflower frame member 28 and which is used for packaging the articles 10lying on platen 12. Accordingly, the packaging areas of the sheet whichlie opposite the articles may or may not be left clear. However, theareas which do not thus overlie the articles may be preprinted with aninscription such as is illustrated in Figs. 4 and 5.

The clamping frame assembly also includes upper clamping unit 38 hingedby means of hinges 40 to the companion clamping unit 28 with which itregisters; An operating handle 42 is provided on frame unit 38 foropening and closing the frame assembly as required to insert andwithdraw plastic sheet 36 Means also are provided for applying heatselectively to the packaging areas of the plastic'sheet: Such meansinclude a heating unit in combination with a shielding unit. The heatingunit, indicated generally at 44 in Fig. 2, includes a substantiallyrectangularframe 46 dimensioned to register with clamping frames 28, 38.An operating handle 48 is connected to the frame and an electric heatingelement 50 is supported thereby. The entire heating unit is mounted on atrack or otherwise for movement toward and away from plastic sheet 36clamped in the clamping frame.

The shielding unit of the selective heating assembly comprises a plate52 fastened by means of screws 54, or otherwise, to the top of upperclamping frame 38. As is apparent from Figs. 2 and 3, shield 52 isformed with openings in predetermined locations. Thus open ings 56,which may assume the form of linearly disposed, round or elongatedopenings, register with ridges 16 on platen 12. Openings 58, which areof comparatively large size, overlie the unprinted areas of plasticsheet 36 and articles 10 on platen 12. Since shield 52 is spaced fromplastic sheet 36 by a distance equal to the thickness of upper clampingframe 38, heat directed against the shield by heating unit 44 will besomewhat diffused, but will be directed against and soften thoseportions of the plastic sheet which are opposite articles 10 and ridges16.

- Operation The manner of operation of the above described apparatus isas follows:

Articles 10 to be packaged are placed on platen 12 opposite vacuumpassageways 20 where they are held by gravity, magnetic attraction orotherwise. The clamping frame assembly is placed in the raised, openposition of Fig. 1.. A sheet 36 of suitable thermoplastic material is,placed across the opening of lower clamping frame member 28 after whichupper clamping frame member 38 is lowered into clamping engagement withthe lower frame member.

Heat unit'50 then is energized or, if continuously energized, movedadjacent the apparatus. Heatthereupon is radiated against shield plate52 which permits application of heat to the plastic sheet only in thoseareas directly below openings 56, 58. The application of heat iscontinued until these areas of the plastic have been softened.

Next, piston rods 32 are retracted, which draws the clamping frame andthe plastic sheet down over the platen and across the articles 10. Avacuum mold box defined by the upper surface of table 14, platen 12, theside walls of clamping frame 28 and the plastic sheet itself accordinglyis formed.

Vacuum is applied to the interior of the mold box via duct 26communicating with'passageways 18, 20, 22 and 24. The softened areas ofthe plastic thus are sucked down; those opposite ridge 16 being formedin a continuous bead about the articles 10, and those opposite thearticles themselves being drawn about and tucked under the articles,encasing and packaging them.

After the heat source has been removed, the plastic sheet is permittedto cool and harden. The clamping frame then may be opened and the sheetwith encased articles stripped from the platen 12. Where, asillustrated, several package units are formed in one operation, thesemay be cut apart from each other.

The final package is illustrated in Fig. 5." It comprises a plasticsheet 60 having a marginal bead 62 conforming to the dimensions of ridge16 on platen 12. This stiifens the sheet and lends rigidity to it forbetter handling during merchandising operations. The articles 10 areencased inthe clear area of the plastic. The preprinted message appearsabove the articles, undistorted and legible.

It is to be understood that the form of my invention herewith shown anddescribed is to be taken as a preferred example of the same and thatvarious changes in the shape, size and arrangement of parts may be madewithout departing from the spirit of my invention or the scope of thesubjoined claim.

Having thus described my invention, I claim:

Apparatus for packaging an article in a thermoplastic sheet havingprinted and packaging areas, comprising support means for supporting anarticle to be packaged, peripheral bead-forming means on the. supportmeans, means for supporting a thermoplastic sheet across thebead-forming means with the packaging area thereof.

overlying the article, heating means adjacent the sheet supporting meanson the side thereof opposite the article supporting means and operableto heat and soften a thermoplastic sheet, heat shielding meansinterposed between the heating means and the sheet supporting means andhaving openings therein disposed for registry with the bead-forming andpackaging areas of a thermoplastic sheet, whereby to heat and soften thelatter and to shield the printed area from such heat, means for loweringthe sheet supporting means to lower the selectively heated areas of thesheet onto the bead-forming means and the article, and means for forcingthe softened areas of the sheet about the bead-forming means and articleand the printed unheated area of the sheet onto the article supportingmeans, whereby to maintain said printed area undistorted, the heatedareas of the sheet thereafter being cooled to harden the same, wherebyto produce a peripherally reinforced package sheet confining an articlein the packaging area thereof and displaying an undistorted printing onthe printed area.

References Cited in the file of this patent UNITED STATES PATENTS1,980,022 Whitehouse Nov. 6, 1934 2,511,024 Toulmin June 13, 19502,536,048 Flanagan Ian. 2, 1951 2,690,593 Abercrombie Oct. 5, 19542,749,572 Nowak June 12, 1956 2,750,719 Wandelt June 19, 1956 2,836,941Hultkrans et a1. June 3, 1958 2,855,735 Groth Oct. 14, 1958 FOREIGNPATENTS 201,271 Australia Mar. 19, 1956

